1. Field of the Invention
This invention relates to hydromassage apparatus, and, more particularly, to a hydromassage apparatus having an air injector system for introducing air into a flow of water.
2. Description of the Prior Art
The field of hydromassage therapy is not a new field. Rather, the value of combining air and water is well known and accepted. For combining the air and water, there are several different types of air injector systems. The term "air injector" refers to the injecting or combining of the air and water. The following group of patents relate to one type of system in which the air supply pipe is disposed within the water supply pipe. The flow of water over or around the end of the air supply pipe, and outwardly into a pool, bath, or the like, results in the combining of the air and the water.
U.S. Pat. No. 3,496,933 discloses an oral cleaning apparatus using air and water. The water is mixed with a cleaning solution and the water and cleaning solution mixture is in turn subject to air pressure prior to discharge through a nozzle. The air injection tube is disposed in the middle of a water supply conduit and the air injector tubing terminates slightly before, or upstream of, the end of the water discharge nozzle.
U.S. Pat. No. 3,672,359 discloses a pair of substantially coaxial conduits, with the center conduit comprising an air conduit, and the outer conduit comprising a water delivery conduit or tube. The air conduit terminates upstream from the end of the outer conduit. The outer conduit includes a restriction extending upstream from the end of the outer conduit. The outer conduit includes a restriction extending upstream from the discharge end of the conduit and terminating slightly upstream of the end of the air conduit.
U.S. Pat. No. 3,905,358 discloses a nozzle apparatus in which a water conduit includes an air injector conduit disposed within the water conduit. The water conduit includes a nozzle, and the air conduit terminates upstream from the throat of the nozzle. The throat of the nozzle is the narrowest portion of the nozzle, or the portion of the nozzle with the least diameter, and the air conduit terminates upstream from the throat. The nozzle comprises a venturi, with the overall cross-sectional of the nozzle at its greatest diameter substantially less than the overall diameter of the water supply pipe.
U.S. Pat. No. 4,082,091, in general terms, discloses a nozzle apparatus similar to that of the '358 patent. The same general venturi type nozzle, with a water supply pipe leading directly into the nozzle, and an air injector pipe terminating upstream from the throat of the nozzle is disposed in the '091 patent, and the overall systems are substantially identical to each other. The '359 apparatus uses household water pressure, which is normally 50-60 psi. The '358 and '091 apparatus typically require high head pumps, with output pressures of 25-35 psi.
There are numerous patents in which the water supply pipe is disposed within the air supply pipe. Rather than having the air supply pipe disposed within a flow of water, the flow of water is disposed within an outer, air supply pipe. Examples of such an air injector system are illustrated in U.S. Pat. Nos. 2,738,787, 3,288,134, and 3,745,994.
Another type of injector apparatus for combining air and water is disclosed in U.S. Pat. No. 3,587,976, in which the air is injected into a water stream forward of the throat of a nozzle. A similar way of injecting air into a stream of water is shown in U.S. Pat. No. 3,628,529. U.S. Pat. No. 3,810,464 also discloses the air supply conduit downstream from the throat of a water supply nozzle.
The air injector systems discussed above generally result in a bubble bath or effervescent effect of the combination of air and water. The ratio of water to air by volume is restricted to about a 50--50 ratio, or in some cases an even lower ratio of water to air. In the latter case, there will be more air than water in the combination and accordingly an increase in the bubble bath type effect. The design of the particular air injector system, or head, as it may be referred to, is therefore determinative as to the net, or overall, effect of the stream of air and water which flows from the hydrotherapy massage system.
In the apparatus of the present invention, air is generally not entrained in the flow of water. Rather, the air effects a breaking up of the continuous or solid flow of the water to provide a pulsating or rhythmic flow of the water against the user of the apparatus. This is different from the apparatus of the prior art, as exemplified by the patents discussed above. The air injector system or head of the present invention results in a flow of air with the flow of water, as contrasted with the bubbly or effervescent effect of the air bubble and water type air injections of the hydrotherapy massage units of the prior art. The apparatus of the present invention results in a stream of water and a stream of air, as opposed to the prior art apparatus which produce a flow of air and water bubbles.
Generally speaking, the effectiveness of a hydrotherapy massage unit varies with the ratio of the stream of air and water emanating from the unit. However, in addition to the effectiveness of a particular nozzle in an air/water unit, another factor is also of importance, and that is the ability to direct the air/water flow from an air injector head to the desired part of the body. This may involve the ability of moving the head of the unit from one location to another location. A detriment to such arrangement is, of course, having the hydromassage units fixed at a particular location. On the other hand, there are substantial advantages to being able to move the head from one location to another. For the use or placement of such hydromassage units or air injector heads in conjunction with a pool, the ability to move the unit from one location on a pool to another location allows substantial flexibility in the end use of the apparatus. The results to be derived from such portability means that a unit may be moved from one part of a pool, where it may be used to massage a portion of a user's body at a particular location or depth of a pool, to another location at the pool where it will be most advantageously used to provide hydromassage therapy to another part of the body. For example, a person standing in a relatively shallow portion of a pool may direct the air/water stream at a lower part of the user's back. By moving the unit to a deeper portion of the pool, the user may remain in a standing position, but the air/water stream may be directed to the user's back or shoulder area. By moving the unit to the extreme shallow portion of the pool, the user may sit on the steps of the pool and have the flow of air and water directed at a foot, leg, or the like. Obviously, such advantages are not possible with a unit disposed at a fixed location.
U.S. Pat. No. 3,674,020 discloses a portable hydromassage unit usable with a swimming pool. The apparatus is self-contained, except that it requires an electrical connection for its operation. A substantial disadvantage of such unit is the requirement of an electrical conductor between the unit and a source of electrical current adjacent the water. The self-contained unit itself includes an electrical motor for providing power for its own water pump. The unit also includes a water intake to provide the required water supply for the pump. The water intake at the unit comprises a potential hazard due to the suction or intake force of the pump. The present apparatus utilizes a high volume, low head pump, as opposed to the prior art high head, low volume pumps. U.S. Pat. Nos. 3,292,615, 3,961,382, and 4,127,117 disclose portable systems adapted to be disposed on the sides of bathtubs. U.S. Pat. Nos. 3,286,712 and 3,534,730 disclose systems placed adjacent a bathtub with a flexible connection between the unit and a nozzle within the tub. U.S. Pat. No. 3,336,921 discloses a self-contained, water-proofed unit disposed within a tub, with an electric cord extending to a source of electrical current. U.S. Pat. No. 4,149,281 discloses a floating system for a swimming pool.